Materials Data on Na(AsO3)2 by Materials Project
Na(AsO3)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.35–2.75 Å. There are two inequivalent As sites. In the first As site, As is bonded to four O atoms to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are a spread of As–O bond distances ranging from 1.71–1.76 Å. In the second As site, As is bonded to six O atoms to form AsO6 octahedra that share corners with three equivalent AsO4 tetrahedra and an edgeedge with one AsO6 octahedra. There are a spread of As–O bond distances ranging from 1.78–1.97 Å. There are six inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two As atoms. In the second O site, O is bonded in a distorted T-shaped geometry to one Na and two equivalent As atoms. In the third O site, O is bonded in a distorted single-bond geometry to two equivalent Na and one As atom. In the fourth O site, O is bonded in a trigonal planar geometry to one Na and two As atoms. In the fifth O site, O is bonded in a trigonal planar geometry to one Na and two As atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Na and one As atom.